The mechanisms by which hyperlipoproteinemia and hypertension influence the extent and severity of cerebral and coronary artery atherosclerosis will be studied. Nonhuman primate models (Macaca fascicularis and Cercopithecus aethiops) will be maintained for up to four years in a two by two factorial design which includes equal numbers of control, hyperlipoproteinemic, hypertensive, and hyperlipoproteinamic-hypertensive animals. The extent of hyperlipoproteinemia, induced by dietary cholesterol, and hypertension, induced by Goldblatt clamp constriction of renal arteries, will be periodically evaluated by blood pressure measurements in each of the experimental animals. Hyperlipoproteinemia will be evaluated by determinations of plasmalipoprotein distribution and structure, including lipoprotein lipid and apoprotein composition and concentration and lipoprotein size measurements. After the experimental period, animals will be killed and pathological evaluation of cerebral and coronary atherosclerosis will be carried out. Multiple regression and multivariate discriminant analyses will be used to identify the most significant relationships between the specific aspects of hyperlipoproteinemia, hypertension, and atherosclerosis. Identification of potential interrelationships between hypoproteinemia and hypertension which are involved in the pathogenesis of atherosclerosis is a major goal of these studies. These nonhuman primate models for coronary and cerebral artery atherosclerosis research will be further evaluated and their suitability documented.